Plumbed the sink waste in today using 28 mm rigid push fit pipe. It's very easy to assemble and I've added a small smell trap. The rigid pipe exits through the van floor then goes into 25mm super flex pipe to the waste tank. It's a good system and the water runs from the sink quite quickly .
Also fitted two ceiling boards and three down lights. It's quite tricky cutting around the wardrobe and shower room, and in hindsight I probably would board the ceiling before building any framework. Very happy with the finished article though and hopefully cut
and fit the last board tomorrow.